MOLLUSCA. : 43 
The species considered by the older naturalists as shells 
and mollusca, are in this system of Lamark distributed into 
three great divisions or classes, which he has denominated 
CIRRHIPEDA, CONCHIFER®, and Moxtuusca. These classes 
he has subdivided according to the following tabular view : 
CIRRIPEDES. 
Animalia mollia, capite oculisque carentia, testacea, fixa. 
Corpus subresupinatum, inarticulatum, tegumenti appen- 
dice involutum, disuper brachiis lentacularibus, cirratis, 
multiarticulatis instructum. 
Os subinferum, non prominulum ; maxillis transversali- 
bus dentatis per paria dispositis. Brachia numero varia, in- 
equalia, biordinata ; singula cerris geminatis, setaceis, mul- 
tiarticulatis, ciliatis tegumento corneo indutis, pediculo im- 
positis. Anus tubum proboscedeum terminans. 
Medulla longitudinalis nodosa, branchiae externee, inter- 
dum absconditz ; circulatio corde vasculisque confecta. 
Testa vel sessilis vel pediculo flexili tendineo elevata ; 
valvis pluribus modo mobilibus, modo ferruminatis, tegu- 
menti appendice intus vestitis. 
OrpRE PREMIER.—CIRRHIPEDES SESSILES. 
Leur corps n’a point de pédoncule, et se trouve enfermé dans une 
coquille fixée sur les corps marins. La bouche est 4 la partie su- 
periéure et anteriéure du corps. 
1. Opercule Quadrivalve. 
Gen. Tubinicelle, Coronule, Balane, Acaste. 
2. Opercule bivalve. 
Grn. Pyrgome, Creusie. 
OrpbrRE SECOND.—CIRRIPHEDES PEDONCULES. 
Leur corps est soutenu par un pédoncule tubuleux, mobile, dont 
